5.  The applicant was born in 1962 and lives in Helsinki.
6.  The facts of the case, as submitted by the parties, may be summarised as follows.
7.  The applicant was suspected of an aggravated drugs offence. On an unspecified date the public prosecutor brought charges against him and two other persons, L.J. and J.J. According to the indictment, the defendants had decided to obtain a large amount of amphetamine from Estonia. Between 28 and 29 September 2001 the applicant and J.J. made a trip to Estonia to arrange the purchase, acting on instructions from L.J. On 15 October 2001 the drugs, hidden in a truck, were brought to Finland by a fourth person. During this period the applicant kept in contact with the Estonian supplier by telephone. On 16 October 2001 the truck driver handed over the drugs to L.J. and J.J., who then hid them. Later in the evening J.J. returned for the drugs, as agreed with L.J. While J.J. was driving back to town, the police stopped and detained him and seized the drugs from his possession. In the meantime, the applicant picked up L.J. from a nearby petrol station.
8.  Subsequently, all the defendants contested the above charge. The applicant denied any knowledge of the matter. He maintained that his trip to Estonia had only been for pleasure and that he had not received any instructions from L.J. relating to it. Nor had he kept any contact with the supplier. He further denied any knowledge of what had happened at the petrol station on 16 October 2001. Apparently all the defendants asserted that their collective enterprise had concerned a plan to purchase weapons and not drugs.
9.  On 1 February 2002 the applicant’s counsel sent a letter to the police inquiring whether all the telephone calls made between the three defendants by mobile phone had been included in the pre-trial investigation material. He also requested the police to confirm in writing that it was not possible to disclose to the defence the telephone metering information in the possession of the police.
10.  In their response of 8 February 2002 the police stated that all the telephone calls pertaining to the investigated offence had been included in the pre-trial investigation material. The police further confirmed that the telephone metering information in their possession could not be disclosed as it was confidential.
11.  The evidence obtained through telephone surveillance and produced before the court included 21 recorded telephone conversations and 7 recorded text messages between the defendants between 25 September and 16 October 2001, apparently all pertaining to the different stages of the alleged drugs offence.
12.  On 14 February 2002 the Espoo District Court (käräjäoikeus, tingsrätten) found that the defendants had planned to purchase drugs and had carried out the plan together. It convicted them as charged and sentenced each of them to six and a half years’ imprisonment. As to the conviction of L.J. and J.J. the court relied mainly on the testimony of the truck driver and the fact that the drugs had been found in J.J.’s possession. As to its finding that all three defendants had acted in concert in committing the offence, the court relied on information obtained through telephone surveillance. According to the court, the numerous recordings of telephone conversations between the defendants consistently showed that there had been a common understanding about the plan to obtain the drugs several weeks before they were delivered. Their co-operation had begun on 28 September 2001, at the latest, when the applicant had made a trip to Estonia with J.J. Since that journey they had been showing concern about the delay in the delivery. The court found the defendants’ account of the plan to purchase weapons unsubstantiated. The court also relied on the recordings in concluding that the applicant had participated in the actual receiving of the drugs just as actively as the other defendants, even though he had not been there to receive them in person.
13.  The applicant, along with the other parties, appealed against the judgment to the Helsinki Court of Appeal (hovioikeus, hovrätten). In his letter of appeal he claimed that all that had been established beyond dispute was that he had made a trip to Estonia and that he had been in contact with the other defendants by telephone, but that did not connect him to the offence of which he had been convicted. The District Court had failed to specify which telephone conversations proved that he had been an accomplice.
14.  In his subsequent additional submission to the court the applicant also requested that the public prosecutor be ordered to produce all the recordings of the telephone conversations between the applicant and other defendants, as they would reveal that the dealings involving the defendants had related to matters other than drugs. The applicant contended that only a fraction of all these telephone conversations had been included in the pre-trial investigation material, thus giving a misleading impression of the nature of their association. If the court were to refuse this request, the defence should at least be granted access to all of the recordings.
15.  The court requested the prosecutor to submit a reply regarding, inter alia, the above request. In his reply of 12 June 2002 the prosecutor stated that it was not disputed that the applicant had been in contact with J.L. and J.J. by telephone also concerning matters other than the purchase of drugs. These conversations had not, however, been included in the case material and had been destroyed, as was required under chapter 5a, section 13 of the Coercive Measures Act (pakkokeinolaki, tvångmedelslag, Act no. 450/1987). Nor did the conversations in question, according to the prosecutor, relate to any other offence which would have allowed the police to keep the recordings without breaching the law. All the conversations that pertained to the matter had been retained, included in the case file and produced to the court.
16.  Having regard to the prosecutor’s reply, the Court of Appeal did not render a decision on the applicant’s request. On 13 December 2002, following an oral hearing, the court upheld the applicant’s conviction. It increased his prison sentence to seven years.
17.  In its reasons the court stated, inter alia, that, apart from the testimonies given by the defendants, there was no evidence to support the allegations about purchasing weapons. Furthermore, the court found the defendants’ testimonies regarding those allegations not credible. It also found inconsistencies between the applicant’s testimony and some of the telephone conversations, which had been played back to the court.
18.  The applicant sought leave to appeal to the Supreme Court (korkein oikeus, högsta domstolen) maintaining that his conviction had been based mainly, and in practice, on the courts’ false interpretation of those telephone conversations which had been included in the case file. The defence had never been given access to a large number of recordings which had not been included therein, although a request to that end had been made during the pre-trial investigation. He submitted as evidence the response given by the police on 8 February 2002. As the recordings were subsequently destroyed, the applicant had been denied the right to assess their relevance for his defence. The applicant renewed his contention that the recordings which had not been included in the case file would have shown that he had been involved with the co-defendants in a transaction not related to the purchase of drugs.
19.  On 19 December 2003 the Supreme Court refused leave to appeal.